While measuring the concentration of a specific solute in a solvent, all we need to know is the ratio of the solute to the solvent. If there are two solutes and one concentration of the two solutes is known, all we need to know is the ratio between two solutes and the concentration of the other solute can be thus calculated. There are various situations requiring the determination of concentrations, such as air quality studies, water quality studies and chemical factory product monitoring. Among others, the studies of clinical diagnostics utilize lots of concentration measurements including measuring the concentrations of glucose, triglycero, cholestride, hemoglobin ureic acid, and oxyhemoglobin. Other possible measurements include the microorganisms such as specific virus, bacteria or its maker or toxin in a human body fluid, especially the blood. Additionally, in enzyme activity studies concerning immuno-tests to antibodies or antigens (such as hormones and enzymes), it is needed to analyze the product of the enzymes or the product of the coupled reactions, the antigen-antibody complex or the labels on the antigen-antibody complex, antigen-enzyme hormone can be protein. Particularly, their concentrations are needed to be determined.
As mentioned before, the concentration of ingredient B in a solution A can be defined to be the ratio of B with respect to the solvent in the solution A. For example, the concentration of glucose (i.e., the ingredient) in blood can be defined as the ratio of glucose with respect to the water in blood.
Although the definition of concentration is clear and straightforward, there exit many problems in putting the measurements of concentrations of solutions into practice. One of the challenges confronted is to measure a solute in a solution in a small time-varying and signal-generating volume in a large stationary container. The time-variance of the volume infers that the volume of the solution or just a volume that contained signal sources. What is in the volume can be liquid, air, condensed matter or ionic solution or a combination of it, being measured is not fixed with respect to time and/or space. The signal generation refers to measuring methods that involve introducing signals into the volumes and the concentration of the signal source can thus be determined by analyzing the induced signal. The problem is that the induced signal will always be mixed up with noise produced by the stationary container and thus, the analyzed result will be hardly accurate. For example, when an infrared light source is directed to a finger of a human body and toward to the blood sample inside the vessel of the finger, both the absorption peaks of water and glucose will show up, together with a lot of scattering noise mainly caused by non-blood stationary sources. Apparently, the noise is detrimental to the accuracy of concentration measurements.
Thus there is a need to provide an apparatus and method for accurately and effectively measuring the concentration of a signal source in a volume. This invention addresses the need.
In one aspect of the invention, there is a method (Mold-In strong method, which means two signals are in a mold-like relationship strongly) for determining a ratio of two signals A(t) and B(t) based on two real signals A′(t) and B′(t) including noise NA(t) and NB(t), respectively, wherein:NA(t)≈NB(t),A′(t)=A(t)+NA(t),B′(t)=B(t)+NB(t), andA(t)=K0*B(t), K0>1,
said method comprising the steps of: (a) performing a mathematical transformation T on both A′(t) and B′(t); and (b) estimating K0 from the following relation:Fi[A′(t)]/Fi[B′(t)]≈K0,
where Fi is the ith order component of the transformation T; and
(c) determining the ratio of two signals A(t) and B(t) from the estimated K0.
In another aspect of the invention, there is a method (Mold-In medium method, which means two signals are mold-like in a medium way) for determining a ratio of two signals A(t) and B(t) based on two real signals A(t) and B(t) mixed with noise NA(t) and NB(t), respectively, wherein:                A′(t) is statistically confident to be not noisy such that NA(t)≈0,A′(t)=A(t)+NA(t)≈A(t),B′(t)=B(t)+NB(t), andA(t)=K0*B(t),        
said method comprising the steps of:                (a) performing a mathematical transformation T on both A′(t) and B′(t); and (b) estimating K0 from the following relation:Fi[A(t)]/Fi[B′(t)]≈K0,        
where Fi is the ith order component of the transformation T and the position of Fi [B′(t)] is identified by the noise around Fi [A(t)]; and (c) determining the ratio of two signals A(t) and B(t) from the estimated K0.
In a further aspect of the invention, there is a method (Mold-In week method, which means two signals are in a weak mold-like relationship) for determining a ratio of two signals A′(t) and B′(t) based on two signals A(t) and B(t) mixed with noise NA(t) and NB(t), respectively, wherein:                A′(t) is a less noisy signal;A′(t)=A(t)+NA(t),B′(t)=B(t)+NB(t), andA(t)=K0*B(t),        
comprising the steps of:                (a) identifying the minimum of B′(t), B′(t)min, by A′(t); and (b) removing the static noise by [B′(t)−B′(t)min].        
In yet another aspect of the invention, there is an apparatus for determining the concentration of a solute in a solvent of a solution in a container having a time-varying volume by analyzing two signals received from the solution, comprising: a detector for measuring the quantity of the two received signals; a signal converter for converting the two signals into two electro-optical signals; and means for determining a ratio of the two electro-optical signals by performing the above-mentioned mold-in methods.
In yet another aspect of the invention, there is an apparatus for measuring the concentration of a solute in a solvent of a solution in a container having a time-varying volume by analyzing two signals received from the solution, comprising: a pressure source for generating the volume change of the time-varying volume; a detector for detecting the two received signal; a signal converter for converting the two received signals into two electrical signals; and means for determining a ratio of the two electrical signals by performing the above-mentioned mold-in methods.
In yet another aspect of the invention, there is an apparatus for measuring the blood pressure variation [P(t)−P(t)diastolic] in a human body by a marker signal B′(t) in the blood of the body, comprising: a detector for measuring the marker signal B′(t); and a data processing unit determining the [P(t)−P(t)diastolic] based on [B′(t)−B′min(t)], where:                P(t) is blood pressure as function of time,        P(t)diastolic is diastolic pressure or minimum of P(t), and        B′min(t) is the minimum of the marker signal B′(t).        